An Integrated Dynamic Approach to the Management of Large Diameter Pre-Stressed Concrete Pipelines

Without a well designed and implemented Infrastructure Asset Management Strategy (IAM), water service providers will be constantly faced with disruptions in their ability to ensure a continuous and reliable supply of clean and safe water. A key component of IAM is pipeline integrity management. The repeat occurrence of pipeline failures in water supplies is an area of concern for the water industry. South Africa does not differ much in risk from the rest of the world due to the poor state of its water pipelines and a lack of understanding of infrastructure asset management. Ageing networks and the lack of asset management strategies at many water utilities and municipalities are the main reasons for the pipe bursts and an inability to supply water. In terms of pre-stressed concrete pipelines, previously, little information was available about the extent and rate of deterioration of the pre-stressing wires in pre-stressed concrete pipelines. Technological innovations have paved the way for improved inspection, monitoring and management of pre-stressed concrete pipelines. Recent developments in electro-magnetic inspection e.g. Eddy Current scanning technology has proved to be a huge success in terms of determining the number and position of wire breaks in pre-stressed concrete pipelines. Managers now have a greater level of information regarding the integrity of the pipeline and through ongoing monitoring can make more informed decisions by monitoring and analyzing trends. While non-destructive technologies e.g. Eddy Current Scanning represents the most accurate means of determining the integrity of the pipeline, operational challenges prevent a more regular means of assessing its integrity. As such, there is a need for the use of non-interruptive technologies to assess the risk of the probability of failure. Non-interruptive acoustic technology (which includes leak detection and fiber optic monitoring) as revolutionized the manner in which pre-stressed concrete pipelines are managed. Current research and development activities are now focused on the development of a fibre optic monitoring system which will provide real-time information regarding the integrity of the pre-stressed concrete pipeline. Finally all data collected through all monitoring technologies and applications are integrated into a web-based risk model to provide an indication of its current condition, enhance management of the pipeline thereby facilitating informed decision making.